What does a freeway mean in California? In the city of San Diego, Interstate 8 is more than a way to get from the desert to the beaches. It has become a political boundary. Since redistricting, newly drawn city council districts no longer cross the east-west freeway.

“It didn’t intend to be a demographic divide,” San Diego State University Geography Professor John Weeks told our reporter Katie Orr. “We do have this historical divide that’s created a demographic divide between the old part of the city, where people have sort of been left behind a little bit and the newer parts of the city, north of Interstate 8.”

San Diego’s northern suburban neighborhoods are home to residents who are wealthier, older, whiter and much more likely to vote Republican. In the central city and southern neighborhoods, residents are on average younger, less well off, more ethnically diverse and more Democratic. And some observers fear that will mean council members will be less willing to reach across the freeway… er, aisle.

Until recently, San Diego had a moderate mayor and a mix of Democratic and Republican city council members from both northern and southern neighborhoods. Now, all the northern council districts are represented by Republicans and all the southern ones by Democrats.

“We all know about the north and south of 8 divide,” said Councilman Todd Gloria. “What I think is perhaps troubling about the current drawings, though, is that there aren’t council members who have a stake on both sides of that fence.”

Will that set San Diego up for political gridlock?

And is it emblematic of California’s divided political geography more broadly?